Variable transmission mechanism yarn package builder



H.P.FRY,JR

Nov. 23, 1954 VARIABLE TRANSMISSION MECHANISM YARN PACKAGE BUILDER Filed Dec. 25, 1950 2 Sheets-Sheet l w T m V W.

Nov. 23, 1954 H. P. FRY, JR 2,694,934

VARIABLE TRANSMISSION MECHANISM YARN PACKAGE BUILDER Filed Dec. 23, 1950 2 Sheets-Sheet 2 Because of the great waste which the quality United States Patent *Ofiice 2,594,934 Patented Nov. 23, 1954 VARIABLE TRANSMISSION MECHANISM YARN PACKAGE BUILDER Horace'P.'Fry, Jr.,Swarthmore,Pa., assignor to American "Viscose Corporation, Wilmington, Del., a corporation ofDelaware Application December 23, 1950, Serial No. 202,475 Claims. :(Cl. 74-104) "The invention relates to the winding of annular strand packages, and particularly to a method and apparatus for eifectinga'desireddistribution of windings in centrifugally formed packages such as cakes of regenerated cellulose yarn.

. In commercial scale centrifugal yarn-collection, such as .in the manufacturing of regenerated cellulose yarn, the yarn is fed into ajspinning bucket in a manner such that the'finished cake has a central passage of approximately cylindrical contour. When the surface of the passage is enlarged (barrel shaped) or narrowed at the middle rather than'cylindrical, there is greater likelihood of disturbing or disarranging the innermost windings of the cake duringthe handling thereof. When this happens, a great many 'layersof windings including many that are not disturbed have to be'removed and discarded to elimin'ate'all of the 'disarranged windings. To overcome this difiiculty, the traverse stroke of the funnel guide through which the yarn feeds into a spinning bucket is adjusted to a 'lengthslightly shorter than the length of the yarnreceiving'isurface of the bucket to compensate for the characteristicallyslower movement of the funnel guide near the ends of its stroke. Otherwise, excessive deposition of yarn would occur near the ends of the bucket and cause the central passage of the cake to be barrel-shaped.

When the ambit of the funnel guide is shortened sufiici'ently to produce cakes having a cylindrical passage, another shortcoming in cake structure becomes evident. It is found that the windings in a belt comprising two or three hundred layers of windings initially deposited in the bucket against its inner peripheral surface do not extend completely to the ends of the box. The later deposited layers are laid immediately over this band and extend around both ends thereof to fill the space between the ends of the band and the inner end-surfaces of the bucket.

many windings of the layers collected 0 Consequently, within the bucket after "collection of the above-named band of windingshave portions which are disposed within the filled-in regions at each end of the box. These strand portions, since they arein contact with or closely adjacent to the inner peripheral surface of the box, are as subject to abrasion, soiling, and other sources of damage as the windings comprising the initially deposited band which are normally considered as having inferior quality and, in normal spinning practice, are stripped from the cake and discarded prior'to further processing treatments. that would be involved, the layers having windings which comprise the above described filled-in regions are not stripped from the cake although these layers include small sections of yarn of is not satisfactory.

It 'is an object of the present invention to provide an apparatus and method by which the average quality of the strand constituting centrifugally formed packages may be substantially increased, and the yardage of yarn stripped from such packages and discarded as waste may be reduced. it is alsoan object to provide inexpensive apparatus which may be used on conventional spinning equipment'withoutexcessive modification thereof. Still another object is to provide an apparatus for producing a desired winding distribution within an annular centrifugally wound "package'which is controlled automati- "cally. 'Other'objects, features-and advantages will be apparent from .thefdllowing' description of the invention thesdrawing relating thereto in which "Fig;irisan'elevation'view of a crank armronstructed o in accordance with one'embodiment' of the invention;

'Fig. 2 is an'elevation' partly in section taken along line 11-11 of Fig. 1;

. Fig. 3 is an elevation view of a crank arm illustrating a modification of the invention;

Fig. 4 is an elevation partly in section taken along line IVIV of Fig. 3;

Fig. 5 is a fragmentarydiagrammatic view in elevation of centrifugal yarn spinning equipment;

Fig. 6 is 'an elevation in section of a modified crank arm assembly;

Fig. 7 is a fragmentary end view of apparatus shown in Fig. 6;

Fig. 8 is a fragmentary end view of another modified crank arm assembly;

'Fig.-9 is a fragmentary 'viewof a crank element used in the crank arm assemblies ofFigs. 6, 7 and 8;

"Fig. 10 is a'fragmentary elevation of another modified crank arm; and

"Fig. 11 is an elevation partly in section taken along line XI'-XI of Fig. 10.

The invention herein described is concerned'with obtaining an annular centrifugally formed strand package havingits outer layers of windings extending the full leng-thof the package and comprises a method and an apparatus for changing the length of thestroke effected by a guide or feeding device relative to a container in which the package isbuilt. Inpracticing the invention, a desired number of layers of windings are first deposited in the container by traversing the'guide over an ambit temporarily extended to a length greater than, and beyond both ends of the ambit employed in forming the remainder of the package; thereafter, .the ambit. is shortened to normal spinning length.

Figs. 1 and 2 illustrate one embodiment of theinvention for effecting a quick changein theeifective lever length of a crank mechanism, :such as illustrated diagrammatically inFig. 5, used to traverse a reciprocating guide-in strand package-building operations. The principal parts of. the apparatuscomprise a reciprocating member 5 having a-slot 6 extending in a direction normal to its path of reciprocation and adapted to receive. a slide block 7 which reciprocates 'withinthe slot when the member 5 drives or reciprocates a crank arm 8-secured to a rocker shaft 9. The reciprocator passes into juxtapositionwith the region swept by the crank arm. The rocker shaft 9 is supported on aifixed axis within a frame It A crank "pin 12 extending-through the slide block 7 in rotatable relationship therewith transmits the drivefrom the reciprocator 5 to the crank arm 8.

The spacing between the crank pin 12 and the rocker shaft-.9, i."6. .the effective lever length therebetween, is adjustable by means of a link 14 to which the crank pin is secured. Although the crank pin 12 is reciprocable within azslot :15 of the crank arm which-extends in a radial direction with respect to the shaft 9, the-position 0 pin in-engagement with a washer 24-,and ainut 25 screwed against a washer 26 inengagement with the link provide the structure for clamping the link to theslide block 22. The slot .15 has sufiicient length to permit adjustment of 'the crank pin 12 relative to the slot 13 of the link 14 as well as adjustmentof the link '14 relative .to the crank arm 8 and the rocker-shaft axis by means of the eccentric member '16.

The ecce'ntricor crank'member .16 comprises twoxshort shafts28 and 29 suppo'rted along-spaced parallel axes by a disc element 30. The member 16 comprises also another disc element 31 secured to the shaft 28 ,by'cap screw '32; a-lever'33is secured to lthe'element 31 to facilitate manual rotation of thezmember. In operation, the member 16 is-rotated through degrees from a position in which-"maximum-spacing is obtained betweenthe shaft 9 and the crank pin 12 to a position in which minimum spacing is obtained, or vice versa. To secure the member in these two different positions, a ball clutch mechanism is used which comprises a recess in the hnk 14 extending from the surface facing the element 31, a spring 34 and a ball 35 housed within the recess, and a pair of diametrically-spaced spherical depresslons 36 1n the surface of element 31 facing the link. Since the link 14 can move only in a direction parallel to its length and that of the crank arm 8, the shaft 28 of the member 16 rotates within a complementary bore in the link 14; consequently, the other shaft 29 of the member necessarily moves while revolving around the axis of the shaft 28 in a direction transversely to the path of movement of the link. To permit such laterial movement of the shaft 29 but to hold it at a fixed distance with respect to the axis of the shaft 9, the shaft 29 pivots within the cornplementary bore of a member 38 rotatably supported on an extension 39 to the shaft 9. A slot 40 of the llnk 14 and the shaft extension 39 extending therethrough provide the necessary structure for limiting the travel of the end of the link 14 adjacent the shaft 9 to movement in a direction parallel to the lengthwise direction of the crank arm 8. The crank arm assembly of Figs. land 2 may be constructed to obtain any desired extension of the normal ambit of a reciprocal guide for feeding strand to a package building spindle, or rotary container such as a spinning bucket commonly used to collect a yarn. The degree of extension is dependent primarily on the spacing of the parallel axes of shafts 28 and 29. The member 16 is therefore fabricated according to any predetermined stroke extension desired by varying the eccentricity of the shafts 28 and 29.

The crank arm assembly which was just described and the others which are hereinafter described are indicated generally by the numeral 44 in Fig. 5. The assembly including the crank arm 8 is mounted on and adjacent the end-portion of the rocker shaft. The rocker shaft and the assembly are oscillated by the reciprocator 5 mounted on a slide bar 45. The oscillating motion is carried from the rocker shaft 9 to a funnel guide 46 through a rocker arm 47, a lifting bar 48 pivotably connected with the arm 47 and connected to the bracket 49. A yarn passes continuously through the guide 46 and is collected in a bucket 50. In accordance with structure found in many conventional spinning machines in use, the slide bar is driven by a cylindrical cam 52.

Figs. 3 and 4 illustrate a modification of the invention in which the structure for connecting the crank pin 12,

the link 14a, the crank arm 8, and the reciprocator 5 is similar. In this embodiment, the invention is applied to the apparatus described in Patent No. 2,586,020.

The apparatus of Figs. 3 and 4 comprises a ratchet wheel rotatably mounted on the shaft extension 39 and provided with a cam groove 56. cited above, a cam follower was fixed to a link corresponding to the link 14a to work within a groove corresponding to groove 56 of the presently described embodiment. In the apparatus now being described, a cam follower 57 constitutes a portion of an eccentric or crank member 58 having another portion 59 which is rotatable with respect to a complementary bore through the link 14a. The cam follower portion 57 of the crank member extends in bearing relation with the surfaces defining the groove 56 of the adjacent cam or bearing member, i. e., the ratchet wheel 55 provided with peripheral teeth 55a which engage a pawl 60 mounted on a stationary pivot 61. The pawl is urged into contact with the wheel periphery by gravity. Thus, as the crank arm assembly is oscillated by the reciprocator 5, the wheel rotates in a counterclockwise direction as viewed in Fig. 3 when the crank arm 8 swings toward the right. The wheel, however, is held from rotating in clockwise direction when the crank arm swings toward the left by engagement of the ratchet teeth with the pawl 60. The surfaces of the cam groove 56 act on the follower 57 to vary the distance between the rocker shaft 9 and the crank pin 12 in a cycle which is repeated at least once for every revolution of the wheel 55.

In this manner, the length of the layers of windings comprising the package may be varied from layer to layer to avoid the formation of the objectionable bands of windings of which a band comprises windings of perhaps two hundred or so adjacent layers in which a winding of alternate layers ispractically in superimposi- In the patent tion. However, such a system does not prevent the formation of shortened layers of windings immediately adjacent the inner cylindrical surface of the bucket and the subsequent filling in around the ends of these layers by the windings of subsequently laid layers. In the presently described embodiment, apparatus is provided for producing layers of extra length in the portion of the cake which is first collected in the bucket by temporarily lengthening the distance between the rocker shaft and the crank pin. In the practice of the invention, rayon yarn cakes of higher average quality and less waste were produced by extending the funnel guide stroke approximately of an inch at each end of its ambit, i. e. a total extension of of an inch.

To obtain this result, the eccentric member 58 comprises a stub shaft 59 having its axis of rotation within the complementary bore of link 14a which is eccentric to the axis of the cam follower 57. The cam follower 57 is secured to the rest of the eccentric or crank member 58 by means such as a cap screw 57a. The member 58 may be rotated to move the link 14a relative to the ratchet wheel, this motion of the link being limited, as hereinbefore described, in a direction longitudinally of the crank arm. A gear 63 is attached to the member 58 coaxially with the stub shaft 59 so that the member 58 may be rotated through 180 degrees to change the effective lever arm length of the crank arm assembly by an automatic control system comprising a motor 64, a solenoid actuated jack device 62, and an automatic timing switch 65.

Electric power is supplied to the system through lines 66 and 67. The motor 64 and the solenoid of the jack device 62 are connected in parallel as shown, or in other arrangements to obtain simultaneous operation when the switch 65 operates to close the circuit to energize the motor and the solenoid. The motor 64 is supported on the link 14a by a bracket extension 68 thereof and connected in drive relationship with the rotatable member 58 by a gear 69 in mesh with the gear 63. A lever 70 is secured to the gear 63 to facilitate manual rotation of the member 58, such as when resetting the automatic control system at the beginning of a doff period, or when entire manual control is resorted to as in case the motor 64 should fail. When full manual control is used, the motor 64 need not be in driving relationship with the member 58. Detents 72 and 73 are fastened to the side surface of the gear and angularly spaced from each other to limit the rotation of the gear to approximately 180 degrees. The gear rotates in a counterclockwise direction from the position shown in Fig. 3, to increase the spacing between the shaft 9 and the crank pin 12, or in a clockwise direction from the position wherein the detent 73 rests against the pin 74 to decrease said spacing. The detents 72 and 73, in stopping the motion of the gear, engage a pin 74 screwed into the link 14a. To secure the gear in one position or the other, a spring 75 is stretched between a pin 76 anchored in the link and the shank 77 of the handle 70 adjacent its anchorage in the gear 63. Shank 77 is so positioned on the gear that the gear rotates past the point of maximum extension of the spring in reaching either position.

When a spinning machine on which the crank arm assembly of the invention is mounted is to be put into operation, the electrical timing switch 65 is set for any desired time period, and the pawl 60 is tilted into the position shown in Fig. 3 wherein it rests against the plunger 62a of the jack 62. The gear 63 is rotated to the position wherein the detent 72 rests against the pin 74. At this setting, the effective length of the crank arm is shortened by the rotation of the member 58 to the position in which oscillations of the rocker shaft 9 of greater angular magnitude are obtained. When member 58 is thus positioned, the ratchet wheel is preferably stopped in a position in which the follower 57 rests within a portion of the cam groove 56 which is nearest the axis of the shaft extension 39 in order to obtain oscillations of largest magnitude and thereby to effect maximum traverse of the guide 46 of Fig. 5. When sufficient time has elapsed the switch 65 closes the circuit for energizing the motor 64 and the solenoid of the jack 62. The gear 63 is-then rotated to the position wherein the detent 73 rests against the pin 74 and the plunger 62a pushes the pawl 60 to a position wherein it falls into engagement with the ratchet wheel 55, as shown in broken outline in Fig. 3. Other arrangements for securing simultaneous movement of the gear. 63'" andthe pa'wl60 may be employdsuchasa slip- "link .(not shown) connecting" the 1gear63 .aiid "thepawl -60. used-in place-of :the solenoid' operated" jack" 62. Such a link wouldv bepivotally:connectedwith:the face of the "gear, 'or in some "other eccentric:relationship"withaxis of rotation .ofathei'member 58, and connected resiliently with thepawLrso that the pawl is liftedout of engagement with the'ratchet wheel whendetent 72 f the gear engage the pin 74 of theishaftextension 39.

Figs. 6'and 7 illustratestill another amodified 'crank arm assembly in which the crank'pin 12',"the"recipr.ocator 5, the crank arm 8b and'the link l lb areconnected'and assembled in'exactly the same'manner 'as the-analogous members of two previously" described embodiments. An eccentric crank device .80 .is providedin the assembly of Pigs. 6 and 7' which is similarto'member16"oflFigs. 1

and.2. In-the embodiment'of Figs. 6 and 7; however, the

shaft or pivot element 81 extends directly into a"slot 82 .in. the crank arm""8b. "The slot'extendsinwardlyifrom .the surface of'ithe crank arm facing :thelink 14b. EThe axle 83 of the member '80 rotates within a complementary bore ofthe link. An annular'lever-supporting.elem'ent '85 is secured to; the axle83. by a screw"86. Alever '87 is secured to the element 85' for'rotating'the'member 80.

The lever 87 is formed with a groove"88"as shown'in- Fig. 9 to.positionuthe:end loop ofwa spring 89 hooked around'the lever. The other end of the spring89 is attached to anieyefi'tting' 90:secured tOFthe-link 14b to hold the member 80 in one position or the other. Element 85 is provided with a small boss or extension 91-.-for-engaging pins 92.0'r'93 which limit the) rotation of the ,member 80. The handle 87 is shown in ghost outlineat 8711.10 indicate its. -pos"ition when rotated to provide. maximum spacing betweenthe crank pin 12 and the rocker shaft9.

Fig. 8 illustrates a' minor modification of the crank arm..assernbly illustrated in Eigs...6- and 7 wherein the link'14b .has a slot 95 instead. ofabore for theiaxle83 of member 80.""The crank arm'Sb has a bore instead of a slot for receiving the extension 81. A pair of pins 96 and 97 extend outwardly from the surface of the link to limit the rotation of the member 80 to the two positions of the member 80 in which minimum and maximum spacing between the shaft 9 and the crank pin 12 are obtained. A spring 89 holds the member in either of the two positions. An automatic control system such as described with respect to the embodiment of Figs. 3 and 4 may be readily incorporated into the modified apparatus of Figs. 6, 7 and 8 as well as the embodiment shown in Figs. 1 and 2.

Figs. and 11 illustrate a modification of the crank arm .assembly illustrated in Figs. 3 and 4 in which rotation bf an eccentric member 100 of Figs. 10 and 11 (analogous to member 58 of Figs. 3 and 4) is obtained by operation of a solenoid-operated jack 101. The eccentric or crank member 100 has a cam follower 103 attached thereto by a cap screw 104 and adapted to work within the cam groove 56. The annular portion 105 of the member 100 has a peripheral groove 106 to store a cable or strand 107 secured to the member at 108 when the solenoid plunger 109 is withdrawn with respect to the solenoid coil 110 into the position as shown. This position corresponds to the setting of the crank arm assembly when extra long layers of windings are being distributed within the bucket 50 of Fig. 5. At such a setting, the cam groove 56 is stopped relative to the follower 103 as shown, and the member 100 is rotated to the position shown to obtain approximately minimum spacing of the rocker shaft 9 from the crank pin 12 since the length of the ambit of the guide 46 is increased as this spacing is shortened. If the minimum spacing is not desired the crank arm assembly may be adjusted to other spacings of the rocker shaft and the crank pin by stopping the ratchet wheel 55 at other positions relative to the cam follower or by changing the point of attachment of a detent 112 to a position clockwise with respect to the face of member 100 from the position shown.

The member 100 is rotated from the position shown when the time switch closes the electrical circuit for connecting the coils of solenoid jacks 62 and 101 to the power supply lines 66 and 67. When this circuit is energized the solenoid plunger 109 is retracted within the coil 110; the cable 107 fastened thereto is pulled to effect, rotation of the member 100 until a detent 113 secured,

thereto engages the pin 114. Simultaneously, the solenoid plunger 62a is actuated to kick the pawl into engagement with ratchet wheel periphery *The assemblymaysbe again prepared for producing thefi lorrger layers of win'din'gs such as" when starting the t collection of a package int-the bucket 50 J-by "setting the time switeha 65-, lifting the pawl 60 back against the plunger-"-62,and-manuallyqeturning 'the*member 100to the position illustrated in Figs. '10 and 11. A-handle 116- attached-to i=themember 100 is provided. to facilitate manual-notation thereof. A- spring lll-s'ecuredto the shank-of-thethandle retains the member 'lllfl in either position.

While preferred embodiments of the invention have been shown'and described, it is. to be understood that changes and variations may be made without' departing from the spirit and scope of the invention as-defined in the appended claims.

I claim:

1. Ina windingrnachine having afrocker- 'shaft and a reciprocator which" isamovable along a path parallel to a normal to the shaft axis, said re'c'iprocator 'having a guide surface extending Lin 'as'direction anormalto and-also transversely to :its path -of movement, mechanism for transmitting the motion 1 of the-reciprocator to the shaft compri'singxa c-rank'arm 'having a guide surface extending in a radialdirection fromthe shaft and in a'cdirection parallel :to the shaft; a crank pin 'slidab'ly supported-on said guide surfaceandextendingtransversely of the crank arm into slidable and rotatable relationship with the guide surface of the reciprocator, -a' link-secured to the crank pin and supported in generally parallel arrangement with thecrank arm, said link and the'shaft each having a surface -in slidable' engagement with a surface of thesother for-limiting the movement of the link in a direction which is radial with 'respectto the shaft; a-bearin'gtmember rotatably supported on the shaft', a 'erank" element havinga surface in bearingirelationship '"With I a surface of "the bearing'member spaced radially from the shaft axis said bearingsurfa'ce extending betwe'en two parallel planes normal to the shaft--axis,'- the crank element' having-another surface in bearing relationship with a complemen tary bore of the link, a time measuring device connected in driving relationship with the crank element for rotating the said element instantaneously through approximately after a desired lapse of time and means for controlling the movement of the bearing member relative to the shaft.

2. In a winding machine having a rocker shaft and a reciprocator which is movable along a path parallel to a normal to the shaft axis, the reciprocator having a guide surface extending in a direction transversely of its direction of movement and transversely of the shaft axis; mechanism for transmitting the motion of the reciprocator to the shaft comprising a crank arm having a slot extending in a radial direction from, and in a direction parallel to, the shaft; a movable link extending in a direction generally parallel to the crank arm and radially with respect to the shaft axis; guide means for limiting the movement of the link in a direction lengthwise of itself; a crank pin secured to the link and extending in a direction parallel to the shaft through the crank arm slot and into rotatable and slidable relationship with the guide surface of the reciprocator; and means for shifting the link lengthwise of the crank arm to carry the crank pin toward and away from the axis of the rocker shaft comprising a rotatable member supported in coaxial relatively rotatable relationship with the shaft, a crank element having eccentric pivotal surfaces, one of said surfaces being in engagement with a cam surface of the rotatable member which is spaced from, and extends continuously around, the shaft axis, the other of said surfaces of the crank element being in engagement with a surface of the link which is complementary thereto and means for controlling the movement of the rotatable member relative to the shaft.

3. In a winding machine having a rocker shaft and a reciprocator which is movable along a path normal to the shaft axis, the reciprocator having a guide surface extending in a direction transversely of its direction of movement and transversely of the shaft axis, mechanism for transmitting the motion of the reciprocator to the shaft comprising a crank arm having a guide surface extending in a radial direction from, and in a direction parallel to, the shaft, a movable link extending lengthwise of the crank arm and radially with respect to the shaft axis, a crank pin secured to the link and extending in a direction parallel to the shaft, and transversely of the guide surface of the crank into slidable and rotatable relationship with the reciprocator guide surface, a ratchet wheel having a continuous cam groove along one side thereof, said wheel supported in coaxial and rotatable relationship with the shaft and with the grooved side thereof facing the link, an eccentric member having two annular surfaces on spaced parallel axes, one of the annular surfaces extending into the cam groove as a cam follower, the other annular surface extending into a complementary bore of the link, friction producing means between the cam wheel and crank arm, a pawl for engaging the toothed periphery of the ratchet wheel, a stationary pivot for the pawl, and means for rotating the eccentric member through 180 to obtain substantial change in the spacing between the shaft and the crank pin.

4. In a winding machine having a rocker shaft, a crank arm mounted on the shaft; 9. reciprocator which is movable along a path parallel to a normal to the shaft axis, said reciprocator having a guide surface extending laterally with respect to its path of movement and in lateral juxtaposition with the region swept by the crank arm; means for connecting the crank arm and a reciprocator in drive relationship extending laterally from the crank arm into slidable engagement with the guide surface, said connecting means being supported adjacent to the crank arm for movement relative thereto in a direction extending toward and away from the rocker shaft; and means for adjusting the connecting means relative to the crank arm comprising an eccentric means supported for rotation about an axis in fixed relation with the crank arm and the shaft on an assembly thereof, and a second eccentric means having one portion extending into pivotal connection with the first eccentric means and another portion eccentric with respect to said first portion extending into pivotal connection with said connecting means.

5. In a winding machine having a rocker shaft, a reciprocator which is movable along a path parallel to a normal to the shaft axis, the reciprocator having a guide surface extending laterally with respect to its path of movement and in lateral juxtaposition with the region swept by the crank arm; a mechanism for transmitting the motion of he reciprocator to the shaft comprising a crank arm having a slot extending in a radial direction from, and a direction parallel to, the shaft, a movable link extending in a direction generally parallel to the crank arm and radial with respect to the shaft axis, guide means for limiting the movement of the link in a direction lengthwise of the crank arm, and a crank pin secured to the link and extending in a direction parallel to the shaft through the crank arm slot and into rotatable and slidable relaionship with the guide surface of the reciprocator; and means for moving the crank pin toward and away from the shaft axis comprising a rotatable member supported on an axis parallel to the shaft in fixed relation with the crank arm and the shaft, the rotatable member comprising cam surfaces in non-concentric relation with its axis, an eccentric member having a portion thereof in engagement with said cam surface of the rotatable member and another portion in eccentric relation with the first named portion in pivotal connection with the assembly comprising the link and the crank member, means for cyclically operating the rotatable member, and detent means for defining the magnitude of rotation of the eccentric member.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,927,307 Carter Sept. 19, 1933 1,968,406 Lambeck July 31, 1934 2,212,909 Wiken Aug. 27, 1940 2,586,020 Fry, Jr. Feb. 19, 1952 FOREIGN PATENTS Number Country Date 140,888 Great Britain Apr. 8, 1920 

